Thoracic Cirripedia from a Southeast Pacific Guyot 
Victor A. Zullo 1 and William A. Newman 2 
A DREDGE HAUL taken at a depth of 228 m from 
a flat-topped seamount (guyot) by the "R/V 
Horizon” in January 1958, during the Scripps 
Institution of Oceanography IGY cruise to the 
southeast Pacific, has yielded specimens of four 
genera of barnacles representing three extant 
suborders of the order Thoracica. The Lepado- 
morpha are represented by a new species of 
Megalasma s. str. Hoek (1883) and by a new 
species of Heteralepas s. str. Pilsbry (1907). 
The Verrucomorpha are represented by a new 
species of Verruca Schumacher (1817), and the 
Balanomorpha by a new species of the subgenus 
Solidobalanus Hoek (1913) of the genus Balanus 
Da Costa (1778). 
Neither Megalasma nor Solidobalanus has 
been previously reported from the eastern Pa- 
cific. The former is but the second member of 
the family Poecilasmatidae known from this zoo- 
geographic province. Heteralepas has been re- 
corded twice from the eastern Pacific: Hetera- 
lepas quadrata ( Aurivillius, 1894) from Lower 
California, and H. cygnus Pilsbry, 1907, pre- 
sumably from Monterey, California. No other 
reports on members of the entire family Hetera- 
lepadidae in the eastern Pacific have been made 
since, although one of us (W.A.N.) has recently 
examined specimens referable to H. quadrata, 
occurring on Panulirus penicillatus (Oliver) 
from the Galapagos Islands. 
Verruca had previously been known from the 
west coast of South America by the extant 
littoral species V. laevigata Sowerby (Darwin, 
1854:520), and from the Pliocene in the vicinity 
of Nome, Alaska, by the presumed littoral spe- 
cies V. alaskana Pilsbry (MacNeil et al., 1943: 
95). In addition to the published fossil record 
of Verruca in the eastern Pacific, several isolated 
1 Systematics-Ecology Program, Marine Biological 
Laboratory, Woods Hole, Massachusetts. (Work sup- 
ported in part by the Ford Foundation.) Manuscript 
received July 1 , 1963 . 
2 Museum of Comparative Zoology, Harvard Uni- 
versity, Cambridge, Massachusetts. 
compartmental plates of a new species of this 
genus from the Oligocene Gries Ranch beds of 
Washington are contained in the Museum of 
Paleontology of the University of California, 
Berkeley ( hereafter referred to by the abbrevia- 
tion UCMP ) . 
The unnamed guyot from which the present 
sample was taken is located on the southwest 
end of Nasca Ridge (Fig. 1) at 85° 25' W, 
25° 44' S, about 1280 km (800 miles) off the 
coast of Chile and 480 km ( 300 miles ) ap- 
proximately N 80° W of San Felix Island 
(Fisher, 1958, fig. 8, station HD-73). A triglid 
fish has been described from the same sample 
(Hubbs, 1959:313-315), and a manuscript on 
a new species of the stirodont echinoid Salenia 
Gray is in press (Zullo, Kaar, Durham, and 
Allison). 
We wish to extend our thanks to Mr. Robert 
H. Parker of the Scripps Institution of Ocean- 
ography for making available the material de- 
scribed in this paper. The descriptions and 
figures of the new species of Megalasma and 
Heteralepas were prepared by W. A. Newman. 
The new species of Verruca and Balanus were 
described by V. A. Zullo and illustrated by Ruth 
L. von Arx. 
suborder LEPADOMORPHA Pilsbry 
FAMILY POECILASMATIDAE Annandale 
Synonymy : Nilsson-Cantell, 1921; Trilasmatidae 
Nilsson-Cantell, 1934^. 
GENUS Megalasma Hoek 
Megalasma ( Megalasma ) elegans Newman, 
sp. nov. 
Figs. 2 A-I 
DIAGNOSIS: Capitulum of five completely cal- 
cified, fully approximate valves; carina with in- 
ternal transverse plate forming a single internal 
355 
SMITHSON I A.. 
INSTITUTION 
JAN 19 1965 
